Wait a minute or two as the device loads the new firmware. You can ping the device at 192.168.1.1 to know when OpenWrt comes online. The WPS light will flash rapidly when OpenWrt begins to initialize, and stay solid when it has finished booting. Also, if you have access to the console (via a serial cable, for example), then you will see that the router first receives the file, then writes the the device, and finally outputs an ok message.